Centrifugal dehydrating and cooling system



June 13, 1950 A. BRAMLEY CEN'I'RIFUGAL DEHYDRATING AND COOLING SYSTEMFiled Dec. 5, 1945 2 Sheets-Sheet 1 I enz grt' lflri rfizw gy June 13,1950 A. BRAMLEY CENTRIFUGAL DEHYDRATING AND COOLING SYSTEM 2Sheets-Sheet 2 HEAT' lNbUl-ATIOD Filed Dec. 5, 1945 Patented June 13,1950 CENTRIFUGAL DEHYDRATING AND COOLING SYSTEM Arthur Bramley, LongBranch, N. J.

Application December 5, 1945, Serial No. 632.825

The present invention relates to processes and apparatus for cooling andpurifying refrigerants, and particularly for cooling, purifying anddehumidifying air.

A purpose of the invention is to cool air by expansion as it enters a,centrifugal cell to a point where it no longer can carry in suspensionthe quantity of water vapor which it previously contained, to forcewater collected from the excess water vapor content out to the peripheryof the centrifuge and to withdraw the water collected through a port atthe periphery.

A further purpose is to cause a fluid to expand bodily inwardly alongthe radius of a centrifuge while under the influence of a centrifugalforce so that the adiabatic expansion of the fluid incident to its flowwill cause areduction in temperature.

A further purpose is to extract energy from the fluid and convert theenergy of the fluid into mechanical energy of rotation by turbine-likebafiies as the fluid flows from a radially outer to a radially innerposition.

A further purpose is to refrigerate by adiabatic expansion of a fluid asit flows from a radially outer to a radially inner position in theannular passage or passages of a centrifuging rotor.

A further purpose is centrifugally to localize water vapor in air, topump off a p rtion of air which is saturated with water vapor and tocool the air which remains by adiabatically expanding it toward the axisof a centrifuge against centrifugal force.

A further purpose is to use in the centrifuge cell radially outerorifices of such dimensions and orientation with respect to thedirection of rotation that they function as ports, preferably coveringthem by a band when they are not in use.

A further purpose is to locate cooling passages in the distribution headof a centrifuge and thus to obtain a better isothermal flow of fluid.

In the dehumidifying of air, a further purpose is to withdraw moisturewhich is present in the air in liquid phase by centrifuging it to theouter part of the body of air being treated and then centrifugallyforcing the water out through a port.

A further purpose is centrifugally to localize moisture which has beenpresent in vapor phase in a body of air treated and then to withdraw theair containing the localized moisture vapor from av point at which it islocalized.

A further purpose is to enhance the emciency of a cooling and treatingsvstem i'mgases or 10 Claims. (C1. 62-137) vapors by forcing the gas orvapor through an artificially cooled distribution head at a pressureabove atmospheric pressure so as to improve the contact of the gas orvapor with the head and therefore improve the metal to gas or metal tovapor thermal conductivity.

A further purpose is to increase the pressure of a gas or vapor which isto be expanded for cooling purposes and therefore greatly increase thecooling benefit to be obtained by the expansion.

A further purpose is to introduce gas or vapor into an expansion chamberat such a low temperature that the rate of cooling is enhanced when thegas or vapor is expanded radially inwardly through a guided path.

A further purpose is to improve the eiiiciency of a cooling system usingair as a refrigerant by greatly increasing the pressure of the air atthe intake to get better cooling eiiiciency, thereby increasing thepressure at the exhaust 0f the cooled air, so as to give higher thermalconduction in the chamber cooled.

A further purpose is to cool air containing moisture to a point where itno longer will retain the same amount of moisture, to centrifuge thesuspended water to the periphery of the centrifuge cell, while by thesame centrifuging some moisture which is retained is localized near theaxis of the centrifuge in a portion of the air having increasedpercentage of moisture content, to withdraw the water from the peripheryand the air having increased moisture concentration from the axis of thecentrifuge and to cool the do"- hydrated air remaining by adiabaticexpansion from the outer part toward the center of the centrifugeagainst centrifugal force.

A further purpose'is to introduce the gas or vapor, which is to beexpanded for cooling purposes, into the rotor through an inlet near theaxis of rotation at such a low temperature and high pressure of 5-30atmospheres that the rate of cooling is enhanced when the gas or vaporis expanded radially inward through a guided passage. To obtain optimumeiflciency, the temperature and pressure should be so chosen that thevirial coemcients in the equation of state would be negative.

Further purposes app ar in the specification and in the claims.

Reference is made to my application for Method of centrifuging andcentrifuge, Serial No. 464,509, filed November 4, 1942, now Patent2,422,882, issued June 24, 1947. See particularly columns '1 and 8 forthe driving mechanism, and columns 1, 'i' and 13 as to coolingmechanism.

Certain refrigeration, dehydration and liquefaction aspects of thepresent invention are included in my continuation in part application,Serial No. 706,739, filed October 30, 1946, for Dehydrating, liquefyingor cooling gas and air. This case is a continuation in part of myapplication Serial No. 417,960, filed November 5, 1941, now abandoned,for Centrifuge and method.

In the drawings one only of the possible embodiments of the inventionhas been illustrated. The drawings have been chosen from the standpointof convenience in illustration and satisfactory explanation of theprinciples involved.

Figure 1 is a diagrammatic central vertical section of a rotor embodyingthe invention.

Figure 1 is a fragmentary section corresponding to a part of Figure lbut taken through an air passage, whereas Figure 1 is taken between thepassages.

Figure 1 is a fragmentary section of a pipe coupling seen in Figure 1.

Figure 1 is a fragmentary side elevation of an outer wall of thecentrifuging cell showing capillary openings instead of the ports inFigure 3.

Figure 2 is a horizontal section of the rotor of Figure 1 taken alongthe line 2-2.

Figure 3 is a fragmentary section upon line 3-3 in Figure 1.

The section upon line |"-l in Figure 3 is shown in Figure 1 In thedrawings like designations, such as letters and numerals, refer to likeparts.

The present invention is directed particularly to the dehumidifying,purifying and cooling of air. The invention can be applied to otherfluids (i. e. gases or vapors or mixtures thereof) which are suitable asrefrigerants.

In diagrammatic Figure l, I illustrate a supporting ring ll) ofphenol-formaldehyde plastic (Bakelite) or other suitable material dishedat II and having suitable clearance at l2 from the wall of the outercentrifuge supporting tube l3. The ring In is mounted on stationarystructure not shown. An annular jet l4 mounted on the lower surface ofthe ring I0, and having orifices l5, introduces air in the space withinand above the ring l0. Air is supplied to the annular jet H by a tubeI6. Co-operating with the ring to i: a tapered upper metallic ring llsuitably fastened to the supporting tube l3 of the centrifuge. The lowerconical surface N3 of the ring I! oooperates with the upper surface I lof the ring In and the air film between these two surfaces supports thecentrifuge in operation.

The ring I! is desirably the rotor of an induction motor whose fieldwinding I9 and field core 20 are shown. The field winding 49 and core 20are mounted on suitable supporting structure, not shown.

The mechanism just described is intended to be any conventional means ofrotating and supporting a centrifuge. It represents a power plant andsupport of any suitable centrifuge which is to be rotated by it.

The device may suitably be fluid (air) supported and air driven, steamdriven or electrically driven in accordance with the proposals of Beamset a1. See article by Skarstrom and Beams, Review of ScientificInstruments, volume 11, page 298 (December 1940); and article by Beamsand Snoddy, Science, volume 85, page 185 (1937). It will be evident thatin the driving means will be required only to the extent that thereaction from the gas issuing from the passsages 4'! and through theblades 61 is insufllcient to rotate the device.

The structure which is rotated together as a unit is included in Figure1 as extending from but not including stationary coaxial pipes or ducts2| and 22 at the top down to but not including stationary coaxial pipesor ducts 23 and 24 and pipe 25 at the bottom.

Whatever the type of motor used, it should be adapted to obtain acentrifugal force of the magnitude of at least two thousand timesgravity. The number of revolutions per second may therefore be twohundred or five hundred. The rotor in the main will be made of anysuitable alloy such as stainless steel.

The invention is primarily applied in cleansing and refrigerating airand in distributing the air to areas of intended use. Since therefrigeration effected is much more effective at increased airpressures, it is intended that a differential between. the pressures ofraw air intake and of discharging refrigerated air be secured either byintroducing raw air under pressure to the centrifuging unit or bywithdrawing air at reduced pressure from the discharge of thecentrifuging unit or as indicated in Figure 1 by both of these methods.Raw air may be cooled within the rotary unit or may be cooled in advanceof introduction to this unit or by a combination of these means.

In purification of the air, the start is made with a normal air product,which for the lack of a better term, will be called raw air. The air hasan indefinite quantity of moisture in vapor phase.

As a result of its difference in specific gravity from the air, thewater vapor, being only about two-thirds of the weight per volume of thelighter component of the air, will consequently be concentrated at orclose to the axis of rotation.

In the present invention it is intended not only to keep the raw aircool while centrifuging to get rid of water in liquid phase but to crowdthe water vapor into a zone near the axis and to withdraw the water aswater at the periphery and the water vapor with whatever oxygen andnitrogen and in whatever proportion from this inner zone. The heavierconstituents of the centrifuging are taken out of this first cell of thecentrifuge into a second cell which is an integral part of the unit; 1.e. rotates at the same speed and about the same axis, i. e., thedehydrated air is withdrawn from one centrifuge chamber to anotherthrough ports near the periphery.

Within the first chamber and during the centrifuging, the constanttravel of the air outwardly toward the periphery will tend to heat upthe air. From the periphery the ports will carry it into another chamberwithout change in the heating content since it will travel from theperiphery of one to the periphery of the other. In the later cell of theunit we have dehydrated air largely. The air is then led from the outerperiphery of the later cell toward the center.

either by the pressure from the first cell or by suction from theultimate chamber into which it is being led, or a combination of thesetwo.

The rotor carries coaxial ducts 26 and 27 which are upwardly directedand which correspond in size and position with the fixed ducts 2i and22. The rotor also carries downwardly directed coaxial ducts 28 and 29which are of the same size and position and correspond therefore withthe lower fixed ducts 23 and 24. One or other of the pairs of ducts atthe upper end and also at the lower end carries couplings adaptedeffectively to seal with the mating ducts by means of flanges II and II,32 and 33, shown as carried by the ilxed ducts above, and 54, I5, 36 and31 rigid with the lower and upwardly directed fixed ducts in Figure 1.These flanges seal effectively against leakage at the high rate of speedintended.

In Figures 1 and 1 are shown fixed and rotatable pipes 25, 39 for acooling liquid, along with a sleeve coupling 40 united to the lower pipeand embracing the upper pipe so as to permit the upper pipe to rotatewith respect to the lowerpipe while supplying cooling water to passages4|, 42 within a distributing head 43. The passages are shown as upwardlydirected at 44 and thence transversely turned at 45 so as to dischargeat 45 down into the inner of the two ducts. This cooled distributinghead is used to prevent increase of temperature of the raw airintroduced through pipe 23. It is needed because the passage 38 providesfor expansion outwardly of the air before it is delivered throughpassage 41 into Since the air introduced into the distributing head hasbeen cooled before entry, some of the water vapor in the air will havebeen condensed into water in the liquid phase and this will be thrownoutwardly at the periphery into the space 45, from which this water canbe drained by opening ports 50 closed by a movable band 5|. This afiordsa means of getting rid at intervals of the water in liquid phase whichwill b thrown out into a space 52 between the body of the centrifuge andan enclosing shell 53.

Microporous porcelain with an average of a billion pores per squareinch, bonded onto a metal backing perforated with fine holes or ports isanother suitable medium for permitting the passage of water or liquidwhile constituting an air seal.

In many applications to refrigerants the enclosing shell 53 should be aheat insulator, its main purpose being to maintain the rotor as near thetemperature of the distributing head as possible and thus minimize theamount of cooling required for the distributing head.

To provide for excess water thrown out through the ports 50, above thatwhich will evaporate within the shell 53, openings 58 are provided fordrainage which takes place when the centrifugal No. 2,422,882 previouslyreferred to and may be fabricated in various ways. One way is byspraying or plating low temperature metals or alloys upon rubber moldsspiked with a network of fibers or very fine wires which may be dissolvd out of the plated material to leave pores of the desired diameter.

6 when the device is used as a refrigerator rather than as an airconditioning unit there is no discharge of fluids from a position nearthe axis of rotation of the centrifuge cell. Referring to Figure 1, thismeans that the exhaust ports 54 will be closed.

The water vapor and lighter air constituents are withdrawn in an axialzone by an exhaust 54 through duct 24.

The heavier constituents of th air which were delivered to thecentrifugal cell 48 at the start remain in the outer part of the cellexcept as they pass on to the second centrifugal cell, the expansioncell 55 through port 56.

The centrifugal action which keeps the heavier fraction out near theperiphery crowds out to this position the dehydrated heavierconstituents of the air from within the cell 48, so that as the heavierconstituents crowd more and more to the outer part of this centrifugecell, the lighter constituents and the water vapor are crowded towardthe axis, from which point they are ultimately discharged through thepassage 54.

centrifuging would itself set up a definit pressurenear the peripheryand to this pressure is added the initial pressure applied to the air atits time of insertion into the rotor. Its transfer through the ports 56does not make any change in the temperature as the transmission at thispoint is at the same diameter as had been occupied by the denser airfraction previously. However, the

air is discharged adiabaticall inwardly toward the center with resultantcooling or refrigeratingeflect.

As the dehydrated air, somewhat overcharged with oxygen, is driven fromits position under some pressure near the periphery of the centrifugingcell and discharged through ports 56 into the expansion cell, it is metby centrifugal pressure .in a reverse direction. Turbine-like blades orvanes 51 tend to force the air outwardly but do allow passage inwardlybetween the blades and the wall through which the discharge may becomeeffective. The movement of the blades prevents the air from laggingcircumferentially in its motion in the cell and requires that the airperform work.

The progress of the discharging air through the compartment 55 is due inpart to the pressure at which the raw air enters the centrifugeunit-where this pressure is used-in part to the concentration of theheavier dehumidified constituents and in part to vacuum conditions atthe discharge if a vacuum be applied there. The fact that work isrequired of the discharging air reduces the temperature.

The parts cross-hatched in Figures 1 and 2 are heat insulation.

From Figure 3 it will be evident that the discharge of the inlet airinto the earlier of the two centrifuging compartments is close to theperiphcry and that the cooling function of the distribution head iseffective to'keep cool the air which is cool before its admission butwhich is being led outwardly radially and therefore has a tendency toheat.

It will be evident that the blades, extending the full height of thelater centrifuge unit or cell have a direction of rotation such thatthey tend to have a pumping action in a direction reverse to thedischarge and tend to back up the content toward the ports as if theywere parts of a centrifugal pump, the pumping action of the bladesfurther eliminating condensed material by back- 16 in it up toward theports 50. The blades tend to act as guides for the discharging air andto prevent it from whirling.

But for the blades there would be a tendency to have succeeding swirlsof decreasing generating radius, each succeeding loop of a spiral lyingwithin the next outer loop as in an Archimedes spiral. Without theblades there would be a very high angular relative speed close to thedischarge ports. The blades have two important functions. Theyreduce-the speed of these whirls, that is. reduce the angular speed ofthe radially inwardly moving dehydrated air and they cause increasedspeed of the unit. They keep the air at the same angular speed near theaxis as the centrifuge, preventing excess speed of the interiorconvolutions of the spiral as they approach the axis. This reducesturbulence.

It will be evident that the cooling depended upon for air conditioningor other purposes to which the final discharge is applied is secured bya combination of initial cooling of the raw air, maintenance of the lowtemperature by the cooling of the distributing head, concentration ofthe dehydrated heavier constituents of the air at a pressure in partattained by the initial pressure of introduction and finally adiabaticdischarge of the air radially toward the center.

It will be evident that the perforations at the periphery for thedischarge of moisture in liquid phase may not only be relatively largeholes or capillary openings but may be of fine grill size if desired.

It will be evident that the cooling cell will be of the same generalcharacter whether the purpose be to cool and purify air which itself isused in air conditioning or for a refrigerant use to handle a gas orvapor other than air which is used as a refrigerant fluid and is notmixed with the air of a room.

It will be evident that where a blade is used, engagement of the fluidcooled with the turbine blades tends to rotate the centrifuge and forthis reason the motor used need not be as large as would otherwise berequired.

It will be evident that the blade action in the present case and theblade action in my Patent 2,422,882 are closely similar and that this istrue notwithstanding the slight difference in the gases handled and inthe ultimate purpose attained.

It will be evident that the separation of the water from the raw air isattained in part by cooling the air to a point where it will no longercarry the water which it previously contained so that a considerablepart of the water can be centrifuged out in liquid phase to and awayfrom the periphery and crowding the lighter constituents in toward thecenter where in vapor phase they may be removed along with the lighterconstituents, that is, air enriched with nitrogen.

In operation, it will be evident that air introduced at the axis, andcontaining moisture, is conducted radially outwardly through passages land 41. The passages will expand the air, converting part of its heatcontent to velocity, and cooling the air. The net effect will be eitherisothermal flow of the air to the periphery, preventing vaporization ofmoisture, or actual reduction in temperature, condensing more moisture.The air when it enters the centrifuging cell, will have liquid moisturethrown oil at the periphery. The dehydrated air will be conducted intothe expansion cell, where it is further cooled while flowing inwardlybetween the blades, the energy of the gas being converted into energy ofthe rotor.

It will be evident that the cooling eilect of the cooled distributionhead may be that required merely to provide for isothermic passage ofthe raw air from the axis to the periphery or may be sui'iicientdesirably to further reduce the temperature of the raw air.

It will be further evident that the guiding effect of the turbinebladeswill reduce turbulence in the air or gas handled and will thus greatlylessen heat transfer conditions in the expansion cell.

It will be evident that there is an advantage in carrying the raw airout to the periphery of the rotor while maintaining it within thedistributing head so that it will be introduced within the centrifugecell at or near the periphery of that cell.

It will be evident that the quantity of moisture in the air will affectslightly the rate at which the raw air can be handled since all of theraw air must pass through the distributing head notwithstanding that thedischarge after purifiestion is confined almost wholly to anoxygen-enriched, purified air product.

It will be evident that my combination of centrifuglng and cooling cellsis highly beneficial whether it handle air which has or has not previousbeen cleansed and use it for air conditioning or handle a refrigerantfluid not intended to be mingled with air nor useful for airconditioning.

Having thus described my invention what I claim as new and desire tosecure by Letters Patentis:

1. Steps in the method of air conditioning using a centrifuge unithaving axial inlet and outlet, a distributing head, a centrifuging celland an expansion cell, which comprise supplying raw air having moisturecontent to the unit at pressures above atmospheric pressure, expandingthe raw air away from the axis of the unit and thereby cooling in thedistributing head, supplying this cooled air to the centrifuging cellnear the periphery, concentrating the heavier constituents of the airnear the periphery and thelighter constituents near the axis of thecentrifuging cell. removing moisture in liquid phase from the heavierconstituents at the periphery and moisture in vapor phase along with thelighter constituents at the axis of the centrifuging cell, transferringthe heavier constituents in the air to the expansion cell and expandingthe heavier constituents radially inwardly to discharge near the axis.

2. Steps in the method of air conditioning using a centrifuge unithaving axial inlet and outlet, a distributing head, a centrifuging celland an expansion cell, which comprise supplying raw air having moisturecontent to the unit at pressures above atmospheric pressure, forcing theraw air away from the axis of the unit through the distributing headtoward the periphery of the centrifuging cell while expanding the rawair and thereby cooling, concentrating the air near the periphery,removing moisture in liquid phase from the air at the periphery,transferring the air to the expansion cell and expanding the airradially inwardly to discharge near the axis.

3. Steps in the method of air conditioning using a centrifuge unithaving axial inlet and outlet, a distributing head, a centrifuging celland an expansion cell, which comprise supplying raw air having moisturecontent to the unit at pressures above atmospheric pressure, expandingthe raw air away from the axis of the centrifuge unit and therebycooling in the distributing head, supplying this cooled air at highdensity at the pc- 16 riphery to the centrifuging cell, concentrating 9the air in the centrifuging cell near the periphery, removing moisturein liquid phase from the air at the periphery, transferring the air tothe expansion cell and expanding the air radially inwardly to dischargenear the axis.

4. In a centrifuge unit having a distributing head, an intermediatecentrifuging cell and an expansion cell, a hollow shaft having air imetand air discharge, rotating with the centrifuge unit, means consistingof walls in the distributing head for expanding the air and guiding itoutwardly to the periphery of the centrifuging cell, dischargeconnections from the centrifuging cell near the axis to the airdischarge, outlet connections for water at the periphery of thecentrifuging cell adapted to allow outlet of water, passages forconducting the heavier fraction of the air from the-peripher of thecentrifuging cell to the periphery of the expansion cell and blades inthe expansion cell inclined with respect to the radius and against whichthe compressed heavier fraction of the air expands axially toward theaxis adiabatically.

5. In a centrifuge unit having a distributing head, an intermediatecentrifuging cell and an expansion cell, a hollow shaft having airinlet, rotating with the centrifuge unit, means consisting of walls inthe distributing head for expanding the air and guiding it outwardly tothe periphery of the centrifuging cell, outlet connections for water atthe periphery of the centrifuging cell, adapted to allow outlet ofwater, passages conducting the air from the periphery of thecentrifuging cell to the periphery of the expansion cell, and blades inthe expansion cell inclined with respect to the radius and against whichair expandsaxially toward the axis adiabatically.

6. A centrifuge including a rotor having a distributing head, acentrifuging cell and an expansion cell, and containing air of highdensity at the periphery of the two cells. a hollow rotor shaft uponwhich the rotor is mounted, spiral channel means for introducing airinto the head through the shaft and for conducting it isothermally tothe periphery of the centrifuging cell, axially located means fordischarging a lighter fraction of the air from the centrifuging cell,means for conducting a heavier fraction of the air from the periphery ofthe centrifuging cell to the periphery of the expansion cell, meanscircumferentially spaced around the periphery of the rotor foreliminating condensed water vapor from the rotor and blades within thepath of fluid flow through the expansion cell for utilizing the workdone by the expansion of the air through reaction against the blades.

7. A centrifuge including a rotor having a distributing head, acentrifuging cell and an expansion cell, containing air of high densityat the periphery of the two cells, a hollow rotor shaft upon which therotor is mounted, spiral channel means for introducing air into the headthrough the shaft and for conducting it isothermally to the periphery ofthe centrifuging cell, meansfot conducting air from the periphery of thecentrifuging cell to the periphery of the expansion cell, meanscircumferentially spaced around the periphery of the rotor foreliminating condensed water vapor from the rotor and blades within thepath of fluid flow through the expansion cell for utilizing the workdone by the expansion of the air through reaction against the blades.

8. A centrifuge including a distributing head, a centrifuging cell andan expansion cell, and having air of high density existing in theperiphery of the centrifuging cell, a hollow shaft upon which thecentrifuge is mounted, means for introducing air into the rotor throughthe shaft and for expanding it isothermally through the-distributinghead to the periphery of the centrifuging ceIkchannel walls forconducting the air from the periphery of the centrifuging cell to theperiphery of the expansion cell, means at the periphery of thecentrifuging cell for eliminating condensed water vapor and blade meansfor utilizing work done by the expansion of the air in the expansioncell.

9. In a centrifuge unit, including a distributing head, a centrifugingcell having an open interior space and an expansion cell, a shaft havingan air inlet, expansion means comprising walls forming curved passagesfor the air inlet leading from the inner part of the distributing headoutwardly to the periphery of said head for expanding flow withresulting temperature fall, and connecting passages between the air inthe distributing head and the periphery of the centrifuging cell.

10. In a centrifuge unit, including a distributing head, a centrifugingcell having an open interior space and an expansion cell, a shaft havinga gas inlet, expansion means comprising walls forming passages for thegas inlet leading from the inner part of the distribution head outwardlyto the periphery of said head for expanding flow with resultingtemperature fall, and means at the periphery of the centrifuging cellfor eliminating condensed vapor. V

ARTHUR BRAm-E'Y.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,004,760 Fetzer Oct. 3, 19111,061,656 Black May 13, 1918 1,123,867 Gue Jan. 5, 1915 1,339,211McKerahan May 4, 1920 1,952,281 Ranque Mar. 27, 1934 2,393,338 RoebuckJan. 22, 1946 FOREIGN PATENTS Number Country Date 633,985 Germany June1, 1937

